Preggo Rats Love Sweaty Hands?

[guyabano]

So at the moment, I've got 4, possibly 5 female rats pregnant in my colony and they ALL love to lick my hands. I'm trying to figure out why they do that and all I could come up with is the fact that they like the salt from sweat residue. Does this mean that they need more salt in their diet or do they just like the taste? This behavior seems to be associated with the recent pregnancies. I used to get the occasional lick, but never this much.

Side note, aren't pregnant rats adorable? When I see them sitting on their bums grooming themselves, I can't help but give the little belly a scratch.